Switch adjusting mechanism



Jan. 8, 1946. M. H. CUMMINGS SWITCH ADJUSTING MECHANISM Filed Sept :50, 1942 IN VEN TOR. Mn vru H. C zmmnas.

ATTORNEY Patented Jan. 8, 1946 2,392,580 SWITCH'ADJUSTING MECHANISM Melvin H. Cummings, North'Caldwell, N. J., as-

signor to Cnrtiss-Wri ration of Delaware ght Corporation, a corpo- Application September 30, 1942, Serial N 0. 460,295

3 Claims.

My "invention relates to adjusting mechanism for switches My invention has particular reference to switch operating mechanism comprising an actuating element adjustable in positionwith respect to an actuating member therefor.

More particularly; my invention relates to operating mechanism for open n a limit switch included in the feather circuit of an airplane pron erwu ope a in m ch m co pr i an actuating element adjustable. in position with respect to a cam surface'which moves toward said actuating element during energization of said feather circuit. 7 Various other objjectsjadvantages and features willbecorne apparent'from'the following detailed des rip on My invention resides in the adjustable switch mechanism, features and combinations of the character hereinafter described and claimed.

For an understanding of my invention and for anillustration of one of theforms thereof, reference is to be had to the accompanying drawing, in which: I

Figure 1 is'an elevational view showing the flanged end of mechanism which is attached to e u of an a r a pr p l r; I

Fig. 2 is a sectional view, partly in elevation, showing the mechanism of my invention; Fig. 3 is a transverse sectional view, partly in elevation, showing the mechanism of Fig. 2'; and Figs. 4 and 5 are views corresponding generally with Fig. 3 and showing different positions of the power-re'ceiving'eltement of the switch.

Referring particularly toFigs. land 2, there is shown a flange I which is disposed at one end of a housing 2 forming part of the power unit and power gear assembly for controlling the pitch of airplane propellers as manufactured by Curtiss- Wright Corporation. This assembly comprises a tubular power member 3 on which is disposed a circular cam 4 having channel configuration as indicated in Fig. 2. The cam 4 is cut away as indicated at 5, Fig. 1, to provide spaced sloping surfaces 5a and 5b, the latter being utilizable as a cam surface as hereinafter described.

Projecting laterally from the housing 2 is a boss 6 defining an interior chamber into which extends a member I provided at one end with a circular channel-shaped section in which is disposed a sealing ring 8 adapted to coact with the adjacent surface of the cam 4.

In accordance with the invention, a screw 9 is mounted, for rotatable movement in opposite walls of the boss 6, the arrangement being such that said screw 9 is swivelled or otherwise suitably mounted so that it is incapable of moving longii e l d r o t na ement th re Ihe exterior threads of the screw Scoactwith threads interiorly formed on the'hub Illof an oscillatory member I I having a depending section Ila adapted to be actuated by the cam surface 512.

' The oscillatory member I I, on the upper'surface thereof, supports a member lzhavlng a fork-shaped upper section lzo coactable with a groove [3a formed peripherally in a-mernber I} which carries a switch contact member I4, said member I3 being mounted for reciprocatoryor slidin movement in suitable manner. The movable switch contact member I I is'coactable with a switch contact member l5 which is fixed to a member ISasecured t0 the propeller hub not shown. As shown in Fig. 2, the contacting ends of the switch members I4 and I5 areenclosed by the telescopically arranged sleeves l6 and i1 formed from suitable electricity-insulating material.

In accordance. with the invention, the oscillatory member I I is slidably related to the member I2, the latter, by reason of the clutching engagement between the fork-shaped end [2a thereof and the contact member I3, remaining stationary when said member ll is moved under the control of thescrew 9. Accordingly, responsive to rotation of the screw 9, the member ll moves in one direction or the other beneath the stationary member I2. Any suitable arrangement maybe provided for slidably relating the'members ll and IZ'for movement with respect to each other. As herein shown, the member I2 is provided'with a T-shaped slot |2b in which is freely received a T-shaped projection Ilb of the lever II. Other equivalent dove-tail arrangements may be used as desired.

As is clearly shown in Figs. 3, 4 and 5, the head So of the screw 9 is disposed exteriorly of the boss 6 as well as the housing 2 so as to be readily engageable by a screw driver. Coactable with said head So of the screw 9 is a suitable locking member l8 utilizable for releasably retaining the screw 9 in a desired adjusted position.

As is well understood by those familiar with the power unit and power gear assembly referred to above, the switch contact members I4 and I 5 constitute a limit switch which is included in the motor-operating feather circuit of the airplane propeller controlled by said assembly. In accordance with well understood practice, when the airplane feather circuit is energized under operator control, the cam surface 5b of the cam 4 moves counter-clockwise, Fig. l, and eventually coacts with known mechanism for moving the hereinbefore described contact member I4 from right to left, Fig. 2, to open the feather circuit as soon as the aforesaid motor has moved the airplane propeller to its proper feather position.

As regards this cam surface 5b, it has been the practice, either to file away or build up the same, by adding metal thereto, in order to effect small changes in the position which the airplane propeller assumes when in feather position. In order to do this, an extensive dis-assembling operation is necessary with respect to the apparatus of said assembly. Such dis-assembling of the mechanism is a factory operation rather than a field operation although it is in the field, rather than in the factory, that changes in the feather position of the airplane propeller are required.

By my invention, minute variations in the feather position of the airplane propeller may readily be effected in the field or in any other place merely by the act of rotating the screw 9 in one direction or the other, this screw being readily accessible from the exterior of the disclosed housing. Thus, it is the depending section Ila of the oscillatory member H with which the aforesaid cam surface 5b coacts and, by properly rotating the screw 9 (the latter, thereafter,

being releasably held in the position to which 10- tated by the locking member 18), said oscillatory member I i is moved with respect to the member l2 to move said dependin section Ila either toward or from said cam surface 5b so as to change in a desired manner the time at which the feather circuit opens, different positions of said depending section Ila being shown in Figs. 4 and 5. v

As will be understood, engagement of the cam surface 5b with the depending section Ila of the member l I causes the latter to rock in a counterclockwise direction, Fig. 2, this rocking movement of the member ll causing the switch contact member M to move from right to left, Fig. 2, under the control of the member [2 and thereby open the feather circuit referred to above.

It will be understood in view of the foregoing, that the switch adjusting mechanism of my invention is specially useful in the application thereof hereinbefore described. However, the invention is not to be thus limited because, obviously, said mechanism may advantageously be utilized for controlling electrical circuits other than the one herein specifically referred to.

While the invention has been described with respect to a certain particular preferred example which gives satisfactory results, it will be understood by those skilled in the art after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended therefore in the appended claims to cover all such changes and modifications.

What is claimed as new and desired to be secured by Letters Patent is:

1. In mechanism of the character described, an actuating member having clutching engagement with a member to be operated, an oscillatory member slidably related to said actuating member, said oscillatory member carrying and serving as the sole support for said actuating member, said oscillatory member comprising an actuatable section, and means for moving said oscillatory member with respect to said actuating member, movement of said oscillatory member as specified changing the position of its actuatable section with respect to an actuating element therefor, said means comprising a screw mounted for rotatable movement only.

2. In mechanism of the character described, an actuating member having clutching engagement with a member to be operated, an oscillatory member slidably related to said actuating memher, said oscillatory member comprising an actuatable section, and means for moving said oscillatory member with respect to said actuating member, movement of said oscillatory member as specified changing the position of its actuatable section with respect to an actuatin element therefor, said means comprising a screw mounted for rotatable movement onb', said oscillatory member carrying said actuating member and said screw carrying said oscillatory member.

3. In combination, cooperative fixed and movable contacts, a switch-actuating cam surface rotatably movable to different positions, means actuated by said cam surface for moving said movable contact from said fixed contact, a housing for said contacts, said cam and said actuated means, said actuated means comprising an oscillatory member, a member carried thereby in slidable relation for actuating said movable contact, and a screw swivelled in said housing, said screw being threaded to said oscillatory member and rotation thereof moving said oscillatory member with respect to said cam surface, said actuating member and said movable contact remaining stationary during the specified movement of said oscillatory member.

MELVIN H. CUMMINGS. 

